Long COVID Research
Below, you'll find a curated collection of recent studies on Long COVID from leading medical journals worldwide.
Research compiled by Jon Douglas. For more information, follow him on X (here).
SARS-CoV-2: A synergy to the Alzheimer’s disease
Research suggests COVID-19 may accelerate Alzheimer’s disease by affecting brain pathways like ACE2 and Aβ42. SARS-CoV-2 invades the brain through the olfactory route, possibly worsening cognitive decline.
Phase-resolved Functional Lung MRI Reveals Distinct Lung Perfusion Phenotype in Children and Adolescents with Post–COVID-19 Condition
54 children studied MRI scans showed reduced lung ventilation and blood flow in children with post-COVID-19 syndrome These changes were linked to higher heart rates and worse chronic fatigue, revealing a distinct lung perfusion pattern.
Defining brain fog across medical conditions
A new review from researchers in the UK explores “brain fog” across multiple conditions, from COVID-19 to chronic fatigue and menopause. It finds brain fog involves cognition, fatigue, and mood but varies widely in cause.
COVID-19 Vaccination and Odds of Post–COVID-19 Condition Symptoms in Children Aged 5 to 17 Years
A US study of 622 children aged 5-17 found that COVID-19 vaccination reduced the odds of post-COVID condition (PCC) by 57% for one or more symptoms and 73% for two or more symptoms.
Plasma exchange therapy for the post COVID-19 condition: a phase II, double-blind, placebo-controlled, randomized trial
A clinical trial in Spain with 50 participants tested plasma exchange therapy for Long COVID. While the treatment was safe, it did not improve symptoms, quality of life, or neurocognitive function compared to a placebo.
Cardiac structure and function 1.5 years after COVID-19: results from the EPILOC study
Southwest Germany, 1154 participants, 1.5 years post-COVID. Those with post-COVID syndrome had subtle heart function declines and lower exercise capacity vs. recovered controls. Changes were mild but highlight the need for long-term heart checkups.
Seasonal variation in the associations between self-reported long-COVID symptoms and IL-6 signalling-related factors (particularly the rs2228145 variant of the IL-6R gene): A clinical study.
Cardiff, UK 175 participants Long COVID risk varies by season and genetics. In summer, AA genotype (IL-6R rs2228145) linked to higher risk, but not in winter. High IL-6 levels were tied to Long COVID year-round.
Characteristics of patients with COVID-19 and smell and/or taste disorders depending on different virus strains: a cross-sectional study in Hiroshima, Japan
Hiroshima, Japan A study of 11,353 COVID-19 inpatients found that smell and taste disorders varied by virus strain. The Delta variant had the highest prevalence (31.66%), while Omicron had the lowest (4.27%).
Interventions for Long COVID: A Narrative Review
A US review of 97 studies on Long COVID treatments found weak evidence for managing fatigue, brain fog, anxiety, depression, and sleep issues. Patients and doctors face uncertainty, often resorting to unproven, costly treatments.
Long COVID has variable incidence and clinical presentations: our 6-country collaborative study
A 6-country study found Long COVID incidence ranged from 17% (Ukraine) to 46% (Mexico), averaging 25%. Most common symptoms: fatigue (47%), hair loss (39.2%), and myalgia (35%). No two countries had the same top 3 symptoms.
Inhibition of kinin B1 receptor alleviates SARS-CoV-2 induced long-lasting cardiovascular complications
In mice, Long COVID harms the heart by activating the kinin B1 receptor. Blocking B1R reduced heart damage, pointing to a possible treatment for lasting COVID-related heart issues.
Immunological and clinical markers of post-acute sequelae of COVID-19: Insights from mild and severe cases six months post-infection
Lyon, France: 40-57% of 458 COVID-19 survivors had Long COVID after 6-9 months. Changes in memory T cells were found, but mostly tied to initial severity. A model predicted Long COVID with 80% accuracy.
Poor Association Between Clinical Characteristics and Seropositivity in Children With Suspected Long COVID—A Single-Centre Study
Stockholm: Study of 113 kids with suspected Long COVID found no strong link between symptoms and antibodies. Both seropositive and seronegative had multiple symptoms, poor health, and high school absence.
Feasibility and acceptance of transdermal auricular vagus nerve stimulation using a TENS device in females suffering from Long COVID fatigue
Vienna, Austria: A study of 36 women with Long COVID found that transcutaneous vagus nerve stimulation (VNS) using a TENS device reduced fatigue and breathlessness over 12 weeks.
Prevalence of erectile dysfunction as long-COVID symptom in hospitalized Japanese patients
A study of 609 hospitalized Japanese men found 19% developed erectile dysfunction up to 2 years after COVID-19. ED was linked to fatigue, breathlessness, depression, and sleep issues but not to COVID-19 severity, reinfection, or vaccination.
Anticoagulant vs. antiviral therapy, recovery and neurodamage in Long COVID: a real-world prospective cohort study
Belgium, 106 patients: Paxlovid was the strongest predictor of Long COVID recovery, while anticoagulants had no effect. Antivirals also lowered neurodamage markers, linking viral persistence to brain injury.
Effect of obesity on the acute response to SARS-CoV-2 infection and development of post-acute sequelae of COVID-19 (PASC) in nonhuman primates
Oregon scientists studied 19 rhesus macaques for 6 months after mild COVID-19. Most showed lasting metabolic and immune changes, suggesting Long COVID may be more common than reported.
Oral Cavity Serves as Long-Term COVID-19 Reservoir with Increased Periodontal and Viral Disease Risk
Chicago, USA, 2020-2024: A study finds that the oral cavity can serve as a long-term reservoir for SARS-CoV-2, increasing risks for periodontal disease and other viral infections. Vaccination reduces but does not eliminate these risks.
Alterations of hepatic lipid content following COVID-19 in persons with type 2 diabetes
Germany, 29 participants. One year after mild COVID-19, people with type 2 diabetes had a 56% increase in liver fat compared to those without infection. No changes in liver stiffness, adiposity, or insulin resistance were found.
Alterations in Gut Microbiome Composition and Increased Inflammatory Markers in Post-COVID-19 Individuals
Brazil, 87 participants: Post-COVID-19 individuals showed increased inflammation (higher IL-17, MPIF-1) and altered gut microbiomes, with a decline in Akkermansia, a bacterium linked to gut health.
Impact of Long COVID on self-reported disease activity, disability, and quality of life in individuals with inflammatory arthritis
Boston researchers studied 283 people with inflammatory arthritis. Those with Long COVID had more pain, fatigue, and worse quality of life, making it hard to distinguish from arthritis flares.
Identifying and mitigating the public health consequences of meta-ignorance about "Long COVID" risks
A US survey of 1,000 adults finds 22% overestimate their knowledge of Long COVID while knowing little. This “meta-ignorance” is linked to vaccine hesitancy, opposition to mandates, and a higher risk of Long COVID.
Pulmonary function and comparative SARS-CoV-2 RBD-specific IgG antibody response among the COVID-19 recovered group
In Bangladesh, 50-66% of COVID-19 survivors had abnormal lung function. Those with severe past infections had the highest antibody levels post-vaccination, but titers dropped within months, highlighting the need for booster shots to maintain immunity.
Reply to: Should we be careful with exercise in post-exertional malaise after Long COVID?
Amsterdam study warns exercise may worsen post-exertional malaise (PEM) in Long COVID. PEM isn’t just deconditioning, and intense activity isn’t a cure.
The health-related quality of life among stroke survivors with post-COVID conditions living in the United States
A study of 3,988 stroke survivors in the U.S. found that those with post-COVID conditions reported worse general health and more days of poor mental and physical health.
Serum Spike Protein Persistence Post COVID Is Not Associated with ME/CFS
Berlin study of 121 post-COVID patients finds spike protein in some up to 31 months after infection but no link to ME/CFS severity. Levels dropped after antibody removal, suggesting binding to antibodies.
Correlation of Interferons and Autoimmune Aspects in Long COVID-19 Patients
Osaka, Japan: A study of 39 Long COVID patients found elevated interferon activity and autoimmune markers, including anti-dsDNA and anti-Sm antibodies, similar to lupus. Researchers propose an interferon-driven autoimmune mechanism for Long COVID.
Longitudinal epigenetic rewiring in lung immune cells in patients with post-COVID-19 condition
Swedish study finds lasting DNA changes in lung immune cells of post-COVID patients, linked to symptoms and heart-lung function. Epigenetic shifts may explain lingering health issues.
Pediatric Gastrointestinal Tract Outcomes During the Postacute Phase of COVID-19
A study of 1.57M US kids found COVID-19 raised the risk of GI issues by 25%, including abdominal pain and diarrhea. Symptoms often lasted over a year, suggesting long-term gut effects.
Profiling the persistent and episodic nature of Long COVID symptoms and the impact on quality of life and functional status: a cohort observation study
UK study of 75 people finds Long COVID symptoms fluctuate over time. Fatigue, brain fog, and breathlessness persist, with little improvement over 16 weeks. Highlights need for better care and support.
Prevalence of cardiovascular symptoms in post-acute COVID-19 syndrome: a meta-analysis
A meta-analysis of 37 studies with nearly 3 million patients found that 15% of COVID-19 survivors experience cardiovascular symptoms like chest pain (22%), palpitations (18%), and hypertension (19%).
Reproducibility of Genetic Risk Factors Identified for Long COVID using Combinatorial Analysis Across US and UK Patient Cohorts with Diverse Ancestries
A UK-US study found 77-83% of Long COVID disease signatures were reproducible, confirming genetic risk. Key genes: TLR4 (immune response), CCDC146 (cognition), D2HGDH (mitochondria), supporting drug repurposing efforts.
Post-Viral Frailty in Long COVID: A Distinct Phenotype within Veterans
A study of 203 veterans found that Long COVID may cause a unique frailty distinct from aging. Unlike geriatric frailty, driven by weakness and slowness, post-viral frailty is marked by exhaustion and low activity.
Molecular and Immunological Signatures of Long COVID: Implications for Diagnosis and Personalized Treatment Strategies
A Dutch study of 72 people found that immune markers and viral RNA help predict Long COVID. Symptomatic men had lower Spike IgG than women. A model using mRNA, antibodies, and inflammation markers improved diagnosis.
Chronic autonomic symptom burden in long-COVID: a follow-up cohort study
A study of 526 Long COVID patients found 72% had chronic autonomic dysfunction, lasting 3+ years. One in three developed POTS, mostly women and those with joint hypermobility. Many couldn’t work due to symptoms.
Long-COVID incidence proportion in adults and children between 2020 and 2024
From 2020 to 2024, a study of 6.4 million COVID-19 patients across the U.S. found that 10-26% of adults and 4% of children developed Long COVID. Risk was highest in older adults, women, and those with severe infections.
Balneotherapy for the treatment of post-COVID syndrome: a randomized controlled trial
Barcelona: 98 adults with Long COVID. Balneotherapy in thermal mineral water improved fatigue, pain, sleep, and anxiety after a month. Some benefits faded later. Safe with mild side effects.
Association of glycemic control with Long COVID in patients with type 2 diabetes: findings from the National COVID Cohort Collaborative (N3C)
In a study of 7,430 patients with type 2 diabetes, poor glycemic control (HbA1c ≥8%) increased the risk of Long COVID, especially respiratory issues and brain fog. The higher the HbA1c, the greater the risk.
SARS-CoV-2 vaccination influence in the development of Long-COVID clinical phenotypes
Rome study (582 people): COVID vaccines cut hospitalizations and lung damage but didn’t stop Long-COVID. Unvaccinated had more neuro issues, while vaccinated had more heart/lung symptoms.
Exploring DNA methylation, telomere length, mitochondrial DNA, and immune function in patients with Long-COVID
Belgium, 358 people: Long COVID patients with fatigue and post-exertional malaise showed shorter telomeres and higher troponin T, linking biological aging and heart involvement to persistent symptoms
Two-year impact of COVID-19: Longitudinal MRI brain changes and neuropsychiatric trajectories
Germany Two-year study of 79 post-COVID patients found lingering brain changes, especially in the brainstem and sensory areas Fatigue improved but remained common Hospitalized patients had more severe effects, hinting at lasting neurological impacts
Long COVID Prevalence and Associated Activity Limitation in US Children
In 2023, 1.4% of US kids had Long COVID, with 0.4% still affected. Older kids and those from lower-income families were most impacted. 80% had activity limitations.
Postacute COVID-19 fatigue, dyspnea and reduced activity in children and adolescents
Switzerland Kids with postacute COVID-19 had more fatigue, breathlessness, and lower activity than peers. Fatigue linked to less movement but not lung function, showing lasting effects.
No impairment of maximal oxygen uptake, pulmonary function and walking economy in patients diagnosed with Long COVID: consideration of disease severity
Norwegian study finds no reduction in oxygen uptake, lung function, or walking efficiency in Long COVID patients who had mild to moderate illness. Suggests symptoms may stem from other causes, highlighting the need for better diagnostic precision.
Cerebral Blood Flow in Orthostatic Intolerance
Duke researchers find cerebral blood flow drops, not heart rate or blood pressure, are key to orthostatic intolerance in POTS, Long COVID, and ME/CFS. Many patients are misdiagnosed. Better CBF measurement is needed.
Long Covid in Older Adults: Functional Outcomes and Treatment Effectiveness
Long Covid worsens daily function in older adults. Paxlovid cuts hospitalizations, Remdesivir lowers death risk, but even vaccination doesn’t stop decline. Nursing home care is crucial for recovery.
Isolated adrenocorticotropic hormone deficiency manifested after COVID-19
A 53-year-old Japanese man developed adrenal insufficiency after COVID-19 due to isolated ACTH deficiency. His symptoms mimicked Long COVID but improved with hydrocortisone.
Long COVID affects working memory: Assessment using a single rapid online test
UK study, 1064 people. Long COVID harms working memory, worst in diagnosed cases. More infections and older age make it worse. Severe brain fog links to the lowest memory scores.